1. Field of the Invention
This invention relates generally to configurations bits and, more specifically, to a circuit wherein unused configuration bits may be powered down to minimize power consumption without having to program the unused configuration bits.
2. Description of the Prior Art
Most processors have one or more peripheral modules. These peripheral modules will generally have a primary configuration bit. The primary configuration bits are used to enable/disable the different peripheral modules. In many cases, the peripheral modules will further have one or more secondary configuration bits. These secondary configuration bits are used to xe2x80x9cconfigurexe2x80x9d (i e., calibrate) the peripheral modules. The secondary configuration bits are used to fine tune elements within the peripheral modules such as resistors, current sources, and other like elements. In many applications, the primary and secondary configuration bits are programmable fuses such as EPROM and EEPROM fuses.
One limitation of configuration bits is that when the configuration bits are unprogrammed, they may draw current. A peripheral module is disabled by programming the corresponding enable/disable configuration bit. When this is done, the corresponding configuration bits that are used to calibrate the peripheral module are no longer necessary. However, if left unprogrammed, the unprogrammed configuration bits will continue to draw current.
Therefore, a need existed to provide a circuit for powering down configuration bits. The circuit would allow any unused configuration bits to be powered down to minimize current consumption when the corresponding peripheral modules are not in use. The circuit would further allow any unused configuration bits to be powered down to minimize current consumption without having to program the unused configuration bits.
In accordance with one embodiment of the present invention, it is an object of this invention to provide a circuit for powering down configuration bits.
It is another object of the present invention to provide a circuit that would allow any unused configuration bits to be powered down to minimize current consumption when the corresponding peripheral module is not in use.
It is still another object of the present invention to provide a circuit that would allow any unused configuration bits to be powered down to minimize current consumption without having to program the unused configuration bits.
In accordance with one embodiment of the present invention, a system for powering down configuration circuits to minimize power consumption is disclosed. The system has at least one first configuration circuit for configuring a peripheral module. A storage element is coupled to the peripheral module and to the at least one first configuration circuit. The storage element is used for enabling and disabling the peripheral module. The storage element is further used to power down the at least one first configuration circuit to minimize current consumption of the at least one first configuration circuit when the peripheral module is disabled. In one embodiment of the present invention, the storage element is a second configuration circuit.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawing.